Drop bottom mine car



June 16, 1942. W M, HAESSLER 2,286,958

DROP BOTTOM MINE CAR Filed April 25, 1941 2 Sheets-sheet 1 EV f INVENTOR June 16, 1942.

w." M. HAEsSLr-:YR

DROP BOTTOM MINE .CAR

Filed April 23, 1941' 2 Shets-Sheet 2 Patented June 16, 1942 UNITED STATES PATENT OFFICE.

2,286,958 nner eo'rroM MINE csa Walter M. Haessler, JerseyCity, N. J., assigner to American Car and Foundry Company, New York, N. Y., a corporation of New Jersey Application April 23, .1941, Serial No. 389,970

(Cl. 10S-308) 18 Claims.

This invention relates to drop bottom mine cars in general and in particular to latch mechanism for drop bottom mine cars in which the doors open in sequence from front to rear.

In the past drop bottom mine cars of the automatic type have been built which are controlled by a latch at the rear of the car releasing the rear door which in turn must be substantially fully open before the next forward door can open. With such a door operation the door at the forward end of the car is not opened until the car has reached substantially the center of the dumping pit, with the result that the coal or other material must drop a considerable distance, necessarily breaking a large percentage of the coal. Recently cars have been built in which the doors are unlatched in sequence from front to rear of the car but most of these cars involve the projection of a latch member beyond the clearance limits of the car, thus allowing the accidental unlatching of the doors during transit. Also cars have been built in which the doors unlatch automatically from the rear toward the front of the car with the unlatched doors dragging on the ties or auxiliary rails until the dumping pit is reached at which time they will open as the car progresses across the dumping pit. Such cars have been referred to as 1-2-3 cars since this is the order in which the doors open and discharge the material into the bin or pit. 5'

It is an object, therefore, of the present invention to provide a mine car having automatic drop bottom doors unlatched from the rear toward the front and opening from the front toward the rear.

A further object of the invention is the provision of an automatic drop bottom mine car having latch mechanism so designed as to automatically release its door upon movement of the next rearward door through a comparatively small angle.

A still further object of the invention is the provision of automatic latch mechanism for drop bottom cars which mechanism is constantly urged toward a released position but is held from release by a lock support or strut carried by the next rearward door.

These and other objects of the invention will be apparent to persons skilled in the art from a study of the following description and accompanying drawings, in which:

Figure 1 is a side elevational view of the car with parts in section or broken away to more fully disclose the construction;

Fig. 2 is a bottom View of the car shown in Fig. 1;

Fig. 3 is a partial end view of the car and disclosing the conventional rear door vand release mechanism; f

Fig. 4 is an enlarged detail view showing the improved latch mechanism in locked position;

Fig. 5 is a sectional view taken substantially on line 5 5 of Fig. 4, and

.Figl 6 is an enlarged sectional view similar to Fig. 4 but showing the parts in their door released position.

Referring now to the drawings in detail, it will be seen that the car is of more or less conventional form, having al front end wall 2, side walls 4 of inclined self-clearing type and a rear end Wall 6. The walls are connected to and supported by a rigid frame formed of side sills 3 joined together by end structures Il! which are adapted to receive the bufng and draft forces incident to transportation of the car. The entire car is supported, as is customary, upon wheels W carrying axles I2, which in the present instance extend completely across the car and through openings in the. side sills. As clearly indicated in Figs. 1 and 3, `the release mechanism for the rearmost door consists of an arm I4 pivotally mounted on the car structure as at I5, carrying a hook I6, the lower end of which is adapted to engage and support a tongue or projection IB attached to the central rear portion of the rear door. This release mechanism is constantly urged into engaged position by means of a spring I9 as well as by the weight of the mechanism itself.

The bottom of the car or, in other words, the 4space between the end sills and side sills is closed by a number of drop bottom vdoors A. B and C lettered respectively from the front toward the rear end of the car. The door A is hung upon a transversely extending hinge rod 20 exetnding through the side sills adjacent the front end of the car and beneath a protecting plate 22 attached. to the side sills and to the front end structure. This door is of any desired form or construction but, as indicated, is provided adjacent its rear or free edge with an upwardly'deflected part 24 stiffened and protected .by a hardened nose piece or lip 25 (Fig. 4). Doors B and C are hung upon transverse hinge rods 28 extending across the car adjacent to but slightly ahead of the car axles. The doors may be hung upon these hinge rods in any desired manner but in order to eliminate wear by distribution of the wear over a large area, the forward edge of doors B and C is rolled around the hinge rod and rotate on the rod. As clearly shown in Figs. 2 and 4 to 6 inclusive, a portion of the forward edge of doors B and C is cut away as at 3l) in order to provide space for the latch mechanism later to be described. In order to prevent loss of lading through the cut-out portion a housing is welded to the door and consists of triangular shaped sides 32 and an upwardly and forwardly sloping rectangular portion 34 capped at its upper edge by the hardened steel lip or wear member 35, thus the cut-out portion or a part thereof is closed by a tent shaped element which will serve the purpose not only of preventing loss of lading but will act as a lock support or strut as will later be explained.

As clearly shown in Fig. l, door C is held by a more or less conventional rear latch, while doors A and B are held by the improved latch mechanism. This latch mechanism consists of a latch member 35 pivotally mounted upon hinge rod 2S and having at least three projections formed thereon. The lower projection 38 is adapted, as clearly shown in Fig. 4, to support the free edge of the adjacent door, while projection 4S is adapted to extend into the closing pathway of the adjacent door in order that the latch member may, as viewed in Figs. 4 and' 6, be rotated in a counterclockwise direction by the free edge of the closing door. The latch member is also provided with a third projection 42 adapted to engage or interlock with the lock member as shown in Fig. 4 or to engage a ledge or stop 44 as shown in Fig. 6 in order to hold the latch member in proper position to engage the closing door to latch the same. As has been indicated, the latch member is freely swingable upon the hinge rod 28 and, as shown, is located at the center of the car, but it is to be understood, of course, that a plurality of these latching members may be placed upon ythe hinge rod 28 in order to support the door at more than one point. The latch member is prevented from swinging movement in the latched position .by means of a lock member d having a forward hook portion 48 and an intermediate semi-circular portion 50 adapted to engage and rotate on the car axle. The lock member is also provided with a projection or supporting ledge 52 adapted to contact the free edge of Wear lip 35, all as clearly set forth in Fig. 4 of the drawings. The lock member is lso provided with a projecting portion 54, through to .the lower outer end of which is passed a bolt or other means 56 to which is attached one end of tension springs Sil. The other ends of the tension springs are connected to anchor plates G2 rotatably carried on the hinge rods 28 upon either side of the latch member 36, but entirely free of connection thereto. During assembly, the springs 60 will be placed under a fairly heavy tension in order that the lock member is constantly urged toward a released position as shown in Fig. 6.

In order to stiffen the car intermediate the end sill structure housings 'HJ of generally inverted V shape are provided extending across the car from side structure to side structure and covering the axle and adjacent hinge rod and latch mechanism. This housing will also prevent loss of lading from the car through the opening between the adjacent doors. As clearly shown in Figs. 4 and 6, the housing has attached thereto a U-shape clip 72 having one flange or stop ledge 44 controlling the motion of the latch member and another flange or stop 'It adapted to contact the hook 'portion 48 of the lock member and limit the rotation of the lock member. It is, of course, obvious that the number of doors on the car may be selected at will and that the three have been used merely for purposes of illustration. It will also be apparent that where the doors are wide or subjected to hard usage, it may be desirable to place more than one latch mechanism at the free edge of the door to support the same.

The latch mechanism may be assembled on the car prior to the securing of the housing 'Iii to the car structure but in most cases it will be found desirable to build the car completely, after which the lock member may be inserted by merely feeding the same in under the housing or hood 10 until the semi-circular portion 59 comes to bear upon its prepared trunnion structure, which in the present case is the axle. The doors may now be hung on the car with the latch members and anchor plates being placed on the rod in the cutout portion of doors B and C. After the doors are hung the springs 6i) are applied and the latch mechanism is held in place and is ready for operation. The operation of the mechanism is as follows, assuming the car to be in a loaded condition, all doors latched: When the car reaches the dumping station the rear wall or master latch will be released by a ramp or trackside structure, thus permitting the rear door C to drop downward to come to rest upon the ties or upon a supporting structure located between the ties. The slight downward motion of door C about its hinge rod 28 will cause the tent-like structure to move downwardly, bringing nose 35 of the lock support member downwardly away from the ledge 52 of the lock member 46. Movement of the nose away from ledge 52 will leave the lock member 46 free to move, which it will do in a counterclockwise direction under action of heavily tensicned springs 53. The springs 6U by rotating the lock member counterclockwise will cause hooked end 48 to release the third projection 42 of the latch member 35. Release of the third projection 42 will permit clockwise rotation of the latch member with the result that the next forward door B will be dropped, coming to rest on the tie or other supporting structure. Release of door B will cause a release of door A in exactly the same manner as just described. As soon as the car reaches the dumping pit the doors, which have been dragging on the ties or supporting structure and are free to drop, will swing open dragging along the pile of material in the pit and consequently opening in the order A-B-C. In other words, the doors are automatically unlatched from rear to front but.- swing to open position from front to rear. In closing, the doors will be pushed to a closed position by sliding over a closing ramp and when the free edge of door A approaches closed position, it will strike projection 4o of the latch member 36 swinging it from the full line position of Fig. 6 to 'substantially the full line position of Fig. 4. This door will be held in the raised position by the closing structure and during forward movement of the car, door B will be brought up into approximately closed position with its lock support or strut 34 through nose 35, forcing the lock member Ito rotate in a clockwise direction. Forced rotation of the lock member in a clockwise direction will tension spring 6G for the next subsequent release action and will at .the same time, due to the bevel of hooked end and bevel of projection 42, force the latch member 36 to the final latched position shown in Fig. 4. Continued forward movement of the car will raise door C causing the latch mechanism between it and door B to operate in the same manner. The `door C, of course, will be held in nal position by the end wall carried latch and all doors will then be held in closed position and the car will be ready to receive another charge of lading.

It will be seen from the preceding description that an automatic latch mechanism has been provided which is positive in action and depends for its action upon the inter-related movement of the adjacent doors. It will also be seen "that due to the peculiar construction of the latch mechanism a slight movement of the rearward door will release the next forward door for dropping. It should also be noted that with the improved latch mechanism no parts f the mechanism project below the lowermost plane of the doors and accordingly the latch mechanism can not be damaged or released during transit of the cars.

While my invention has been described more or less in detail, it will be obvious to persons skilled in the art that various modifications and rearrangements of parts, other than those shown and described, will suggest themselves and all such modifications and rearrangements of parts are contemplated as will fall within the scope of the appended claims defining my invention.

What is claimed is:

l. In a drop bottom mine car, a plurality of pivotally mounted doors, latch mechanisms retaining certain of said doors in raised position, each of said mechanisms comprising a latch member supporting the free edge of its associated door, a lock member engaging said latch member to retain the same in door supporting position, and means carried by the adjacent door at a point removed from the pivot thereof, said means freely engaging and disengaging a part of said lock member to control movement thereof.

2. In a drop bottom mine car, a plurality of pivotally mounted doors, latch mechanisms, retaining certain of said doors in raised position, each of said mechanisms comprising a latch member supporting the free edge of its associated door, a lock member engaging said latch member to retain the same in door supporting position, resilient means constantly urging said lock member out of engagementwith said latch member, and means carried by the adjacent door adjacent the pivoted edge thereof to control movement of said lock member.

3. In a drop bottom mine car, a plurality of doors pivotally carried at their forward edges on axes extending transversely of the car, latch mechanisms for supporting the doors when in raised position forming the drop bottom of the car, certain of said latch mechanisms comprising a latch member carried by the oar and adapted to be held in position to support the rear free edge of a forward door, a lock member carried by the car in position to engage said latch member, and means carried by the forward portion of the adjacent rearward door at a point removed from its pivot, said means freely engaging and disengaging a part of said lock member to retain said lock member in engagement with the latch member when said rearward door is in raised position to thereby hold the latch member in door supporting position.

4. In a drop bottom mine car, a plurality of doors pivotally carried at their forward edges on axes extending transversely of the car, latch mechanisms for supporting the doors when in raised position forming the drop bottom of the car, certain of said latch mechanisms comprising a latch memberl carried by the car and adapted to be held in position tc support the rear free edge of a forward door, a lock member carried by the car in position to engage said latch member, and means carried by the forward portion of the adjacent rearward door at a point removed from its pivot, said means freely engaging and disengaging a part of said lock member to retain said lock member in engagement with the latch member when said rearward door is in raised position to thereby hold the latch member in position supporting the rear free edge of the forward door, said means comprising a projection forcing said lock member into engagement with the latch member during final movement of said rearward door into raised position.

5. In a drop bottom mine car, a plurality of doors pivotally carried at their forward edges on axes extending transversely of the car, latch mechanisms for supporting the doors when in raised position forming the drop bottom of the car, certain of said latch mechanisms comprising a latch member carried by the car and adapted to be held in position to support the rear free edge of a forward door, a lock member carried by the car in position to engage said latch. member and being constantly biased toward latch member disengaging position, and strut means carried by the adjacent rearward door to force said lock member into engagement with the latch member during final movement of said rearward door into raised position to thereby hold the latch member in position supporting the rear free edge of the forward door.

6. In a drop bottom mine car, a plurality of doors pivotally carried at their forward edges on axes extending transversely of the car, latch mechanisms for supporting the doors when in raised position forming the drop bottom of the car, certain of said latch mechanisms comprising a latch member carried by the car and adapt-v ed to be held in position to support the rear free edge of a forward door, a lock member carried by the car in position to engage said latch member, resilient means carried by the car and constantly urging said lock member ont of engagement with the latch member, and a projection carried by the next rearward door for overcoming said resilient means to force the lock member into engagement with the latch member during final movement of said rearward door into raised position to thereby hold the latch member in position supporting the rear free edge of the forward door.

7. In a drop bottom mine car, a plurality of doors pivotally carried at their forward edges on axes extending transversely of the car, latch mechanisms for supporting the doors when in raised position forming the drop bottom of the car, certain of said latch mechanisms comprising a latch member carried by the car and adapted to be held in position to support the rear free edge of a forward door, a lock member carried by the car inposition to engage said latch member, resilient means carried by the car and constantly urging said lock member out of engagement with the latch member and a projection carried by the next rearward door for overcoming said resilient means to force the lock member into engagement with the latch member during final movement of said rearward door into raised position to thereby hold the latch nember in position supporting the rear free edge of the forward door, said projection moving away from said lock member during dropping of said rearward door, whereby said resilient means may move the lock member out of engagement with the latch member thereby allowing the latch member to release the said forward door for dropping.

8. In a drop bottom mine car, a plurality of hinge rods extending transversely of the car, doors hinged at their forward edges on said rods, latch mechanisms supporting the free or rearward edges of the doors when in raised position forming the drop bottom of the car, certain of said latch mechanisms comprising a latch member pivotally mounted on the hinge rod of a rearward door and swingable into position to support the free edge of the next forward door, a projection on said latch member, a lock member pivoted on an axis substantially parallel to the hinge rods and having a hooked end engageable with said projection to retain the latch member in door supporting position, and a lock support extending upwardly from said rearward door into engagement with said lock member when said rearward door is in raised position thereby retaining said hooked end in engagement with the latch member to retain the forward door in raised position.

9. In a drop bottom mine car supported on wheels and axles, a plurality of hinge rods extending transversely of the car forward of said axles, a door carried on each of said hinge rods and forming the drop bottom of the car when in raised position, a latch member pivotally mounted on a hinge rod in position to engage the rear free edge of the next forward door, a lock member pivotally mounted on an axle and in position to engage said latch member, a strut carried by the adjacent rearward door rearward of the axle and movable during raising of the door upward into engagement with the lock member to force the lock member into engagement with said latch member to thereby hold the latch member in position supporting the rear free edge of the next forward door.

10. In a drop bottom mine car supported on wheels and axles, a plurality of hinge rods extending transversely of the car forward of said axles, a door carried on each of said hinge rods and forming the drop bottom of the car when in raised position, a latch member pivotally mounted on. a hinge rod in position to engage the rear free edge of the next forward door, a lock member pivotally mounted on an axle and in position to engage said latch member, a strut carried by the adjacent rearward door rearward of the axle and movable during raising of the door upward into engagement with the lock member to force the lock member into engagement with said latch member to thereby hold the latch member in position supporting the rear free edge of the next forward door, and resilient means urging said lock member toward latch member releasing position whereby said latch member will be released upon slight downward movement of said strut.

1l. In a drop bottom mine car, a pivotally mounted drop door, a pivotally mounted latch member with which the free edge portion of said door is engaged when said door is in closed position whereby said door is supported, a second pivotally mounted drop door, a lock member releasably engaging said latch member above its pivot mounting to retain said latch member in door supporting position, and means carried by said second drop door so arranged as to releasably engage said lock member to control the movement thereof.

12. In a drop bottom mine car, a pivotally mounted drop door, a pivotally mounted latch member with which the free edge portion of said door is engaged when said door is in closed position whereby said door is supported, a second pivotally mounted drop door adjacent said first-named door, a lock member having one end portion release-bly engaging said latch member to retain said latch member in door supporting position, and means carried by said second door and releasably engaging another portion of said lock member to retain said latch member in door supporting position.

13. In a drop bottom mine car, a pivotally mounted door adapted to swing from closed to open position by gravity, a pivotally mounted latch member with which the free edge portion of said door is engaged when said door is in closed position whereby said door is supported, a second pivotally mounted drop door adapted to swing from ose to open position by gravity, a lock member having one end portion releasably engaging said latch member to retain said latch member in door supporting position, and means carried by said second-named door and releasably engaging another` portion of said lock member when said second door is in closed position to retain said latch member in door supporting position, said means being releasable from said lock member upon swinging movement of said second door to open position.

14. In a drop bottom mine car, a pivotally mounted door adapted to swing to open position by gravity, a pivotally mounted latch member with which the free edge portion of said door is engaged when said door is in closed position whereby said door is supported, a pivotally mounted lock member formed to releasably engage said latch member to retain the latter in door supporting position, spring means constantly urging said lock member out of engagement with said latch member, a second door adapted to swing to open position by gravity, and means on said second door engaging said lock member when said second door is in closed position to retain said lock member in engagement with said latch member, said means being releasable from .said lock member upon swinging of said second door to open position to permit said spring means to release the lock member from engagement with said latch member.

15. In a drop bottom mine car having wheels and axles, a pivotally mounted drop door, a pivotally mounted latch member with which the free edge portion of said door is adapted to engage whereby said door is supported in closed position, a second drop door carried by the pivot for said latch member, a lock member supported on a car axle and releasably engaging said latch member to retain the latter in door supporting position, and means on said second door arranged to engage said lock member when said second door is in closed position to retain the lock member in' engagement wih said latch member, said means being releasable from said lock member upon swinging movement of said second door to open position.

16. In a drop bottom mine car having wheels and axles, a pivotally mounted drop door, a pivotally mounted latch member with which the free edge portion of said door is adapted to engage whereby said door is supported in closed position, a second drop door carried by the pivot for said latch member, a lock member supported on a car axle and releasably engaging said latch member to retain the latter in door supporting position, means on said second door arranged to engage said lock member when said second door is in closed position to retain the lock member in engagement with said latch member, said means being releasable from said lock member upon swinging movement of said second door to open position, and means secured to a car part with which said lock member is adapted to contact to limit the amount of release movement thereof.

17. In a drop bottom mine car comprising a frame, wheels and axles, a hinge rod secured to the frame, a drop door, a latch member supported by said hinge rod and formed to engage the free end portion of said drop door to support the latter in closed position, a second drop door supported by said hinge rod and adapted to swing to open position by gravity, a lock member pivotally supported by an axle and formed to releasably engage said latch member to retain the latter in door supporting position, and means carried by said second door in position to engage said lock member when said second door is in closed position to retain said lock member in engagement with said latch member.

18. In a drop bottom mine car comprising a frame, wheels and axles, a hinge rod secured to the frame, a drop door, a latch member supported by said hinge rod and formed to engage the free end portion of said drop door to support the latter in closed position, a second drop door supported by said hinge rod and adapted to swing to open position by gravity, a lock member pivotally supported by an axle and formed to releasably engage said latch member to retain the latter in door supporting position, and means carried by said second door at a point removed from said hinge rod and formed to engage said lock member When said second dooris in closed position to retain said lock member in engagement with said latch member.

WALTER M. HAESSLER. 

